Temperature Effect Analysis On The Steel-concrete Composite Bridge Deck Of Long-span Suspension Bridge

With the rapid development of social economy, much of the infrastructure is suffering a severe test due to the following increase in traffic load. The disease of bridge deck is a serious problem that many bridge structures commonly faced for such kinds of traffic loading, especially in the large-span suspension bridge. While the application of steel-concrete composite bridge deck system brings a new opportunity for this condition, its unique construction significantly improve the overall bending strength and optimize the mechanical performance, which make it have a very considerable development prospects. But the research on temperature effect of this new type structure is very scarce in present, existing analyses are almost based on the related regulations of current bridge criterion in China, in which three-dimensional temperature field is simplified to one-dimensional, ignoring the influence of the longitudinal and transverse temperature gradients, this method is largely simplified the calculation process, but have a big difference with the practical situation. When the solar radiation intensity is higher, steel girder is so sensitive to the ambient temperature that can heat up quickly in a short time, which leading to an obviously different temperature along the orientation of vertical and lateral. So this paper combined the field measurement with finite element simulation to analyze the effect which the reference temperature in specifications impact on the steel-concrete composite bridge deck. The main work as follows:By reviewing relevant literatures at home and abroad, this paper made the detailed introduction to the theoretical calculating methods of temperature stress for steel-concrete composite bridge deck system. A new concept was brought in to optimize the traditional computing model and the validity is proved with an actual project. On that basis, the longitudinal and transverse temperature distribution curve of steel truss beam under the most unfavorable condition was fitted through the field measured data that relied on the project of Aizhai Bridge. Meanwhile the simulation was conducted by Ansys program, according to the relevant provisions on the temperature in general specification, combined with the field measured data to analyze the temperature effect under different working conditions for the steel-concrete composite bridge deck of long-span suspension bridge, and emphatically discussed the influence which the longitudinal and transverse temperature gradient of steel truss stiffening girder impact on the stress of it. The results show that the temperature effect on the composite bridge deck system is significant, and the transverse temperature difference of steel truss beam have a great influence on the stress of composite bridge deck so that should be taken into consideration when design, but the effect that longitudinal temperature difference impact on is small, which can be ignored.